Removal of sulphur and sulphur compounds from hydrocarbon oil



Patented Feb. 7, 1928.

UNITED STATES PATENT "OFFICE.

GERALD L. WENDT, OF CHICAGO, ILLINOIS, ASSIGNOE '10 STANDARD OIL COMPANY, OF WRITING, INDIANA, A. CORPORATION 01 INDIANA.

REMOVAL OI SULPHUR AND SULPHUR Ho Drawing.

The present invention relates to the removal of'sulphur and sulphur compounds from hydrocarbon oil, and particularly the lighter oils, such as gasoline, naphtha, burn- 6 ing oils, and the like. It has to do more particularly with the treatment of those oils which, after sweetening with the usual sodium plumbite or doctor solution, or rerunning are found to again become sour;

10 that is, indicate by doctor and corrosiontests the presence of sulphur compounds.

In refinery practice,'many distillate oils are sweetened, or treated with aqueous sodi-v um plumbite (doctor) solution (with or without added sulphur) and are subsequently redistilled; With many of these oils it is found that the redistilled oils show the presence of hydrogen sulphide, and are again sour-7. A particularly important example of such oil is found in pressure distillate, the distillate from oils cracked under pressure for the formation of lighter oils, such as gasoline.

The present invention has for its sub'ect a the complete removal of sul hur and sulp ur compounds from hydrocar on oils particularly of the type hereinbefore referred to, which, when treated with aqueous doctor solution, again becomes sour on rerunning.

In accordance with this invention, the oils to be sweetened are treated with an alcoholic solution of sodium hydroxide saturated with litharge. It' is preferred that the strength of alcohol in the solution be in excess of as and preferably from 7 5 to 90% in strength.

In. preparing the alcoholic plumbite or doctor solution, an alcoholic solution of sodium hydroxide containing from 5 to 20% of sodium hydroxide is repared, and 0.1 to 1% 1' of litharge. The acoholic plumbite or doc- Application filed July 18,

tor solution is then employed in the same manner as aqueous solutions of plumbite are now employed. If desired, the oil may be treated first with an aqueous doctor solution, and subsequently treated with the alco- 45 holic plumbite solution, an appreciable economy in the loss of alcohol being thereby effected. The alcoholic plumbite solution may be used on the oil in proportions of 1 part ofthe plumbite solution to 15 to '50 parts by on volume of the oil.

By treating the oil in accordance with the present invention, it is found that oils which, after treatment with aqueous doctor solution alone, becomes sour on rerunning or redistillation, remain sweet. In other words, the alcoholic plumbite solution removed from the oil, in addition to the sulphur compounds removed by aqueous doctor solution, those which remain in the oil and break down on 'redistillation with the formation of compounds imparting sourness to the oil.

I claim:

1. The method of refining hydrocarbon oils for the removal of sulphur therefrom e5 comprising subjecting the oils to the action gf an alcoholic solution of sodium plumite.

2. The method of refinin hydrocarbon oil distillates comprising was ing a hydrobite.

GERALD L. WENDT. 

